Two men arrested in the triple homicide of a Clark, Wyoming family told authorities they went to the house armed with stolen guns, intending to steal an SUV, but instead left behind a scene of bloodshed that has stunned the rural community.

Tanner Vanpelt, 18, and Stephen Hammer, 19, both from Cody, Wyo., appeared in court today to face charges, including murder and robbery, in a case authorities are calling "nothing short of cold-blooded murder."

The bodies of 40-year-old Ildiko Freitas and her parents, Janos Volgyesi, 69, and Hildegard Volgyesi, 70, were discovered at 11:27 a.m. Saturday, less than an hour after they were shot to death in their home during a robbery. The garage door to the family home was left open and their black Audi SUV was missing.

Neighbors said they saw two men arrive at the family's home Saturday morning in a white Ford Taurus. Nineteen minutes later they saw the sedan and the family's black Audi SUV drive away from the home at a high speed, according to a an affidavit obtained by ABCNews.com.

Police located the vehicles several miles from the crime scene and arrested Vanpelt and Hammer without incident.

After his arrest, Hammer told authorities he was sorry for "shooting that lady" and that he realized authorities likely already knew the men used guns stolen from a Cody sporting goods store to carry out the triple homicide, according to the affidavit.

Hammer and Vanpelt guided investigators to an irrigation pipe several miles from the scene where they had stashed guns, the affidavit said, and began talking to police.

"Vanpelt admitted that he had got into an argument with Ildiko over the black Audi and the fact that they needed the car. Vanpelt stated that Ildiko walked into the kitchen and they were arguing more," the affidavit said. "Vanpelt then pulled out his gun and shot her once in the head."

Hammer told authorities he then shot Hildegard Volgyesi after she startled him by the basement stairs, according to the affidavit. The documents said Vanpelt shot her two more times after he saw she was still alive.

Vanpelt told authorities he had been trying to start the black Audi SUV when Janos Volgyesi entered the garage, according to the affidavit.

When Volgyesi turned to hang something on the wall, Vanpelt told investigators he shot him twice in the back, the affidavit said.

Neighbors reported seeing the white sedan and the black Audi speeding away from the home at 11:01 a.m.

Less than half an hour later, a Good Samaritan who had found the family's dog wandering and came to return it, discovered the bodies and called 911.

Janos Volgyesi was "laying in a fetal position with blood coming from his mouth" in the garage, while his wife, Hildegard, was shot dead near the stairs, with an apparent bullet wound to her lower left cheek, the affidavit said.

In the kitchen, an ambulance crew tried to save Ildiko Freitas, who was moaning when authorities discovered her in a pool of blood. She died at the scene.

The crime has rattled the picturesque town near Yellowstone National Park, where almost everyone knows everyone else, Park County Sheriff Scott Steward told ABCNews.com.

"You're talking about a small community where a lot of the EMS, a lot of the fire officials knew this family," he said.

Freitas' brother, Thomas Volgyesi, told The Associated Press Monday that he knew of no connection between the suspects and his family.

Volgyesi said his parents retired to Wyoming four years ago for its more relaxed lifestyle, after leaving their longtime home in Southern California.

"They were the only family I have and I'm left with nothing now," Volgyesi told the AP Monday. "To have them taken away from me like this, I'm not registering it yet."

Hammer and Vanpelt will be appointed public defenders and are being held without bond until their next court appearance.